Jackson Data Binding Source Code

Jackson is "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java".

  • Jackson Data Binding module allows you to converts JSON to and from POJO (Plain Old Java Object) using property accessor or using annotations.
  • Jackson Databind Source Code files are provided in the source packge (jackson-databind-2.12.4-sources.jar). You can download it at Jackson Maven Website.

    You can also browse Jackson Databind Source Code below:

    ✍: FYIcenter.com

    com/fasterxml/jackson/databind/ser/std/AsArraySerializerBase.java

    package com.fasterxml.jackson.databind.ser.std;
    
    import java.io.IOException;
    import java.lang.reflect.Type;
    import java.util.Objects;
    
    import com.fasterxml.jackson.annotation.JsonFormat;
    
    import com.fasterxml.jackson.core.*;
    import com.fasterxml.jackson.core.type.WritableTypeId;
    
    import com.fasterxml.jackson.databind.*;
    import com.fasterxml.jackson.databind.introspect.AnnotatedMember;
    import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
    import com.fasterxml.jackson.databind.jsonschema.SchemaAware;
    import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
    import com.fasterxml.jackson.databind.node.ObjectNode;
    import com.fasterxml.jackson.databind.ser.ContainerSerializer;
    import com.fasterxml.jackson.databind.ser.ContextualSerializer;
    import com.fasterxml.jackson.databind.ser.impl.PropertySerializerMap;
    
    /**
     * Base class for serializers that will output contents as JSON
     * arrays; typically serializers used for {@link java.util.Collection}
     * and array types.
     */
    @SuppressWarnings("serial")
    public abstract class AsArraySerializerBase<T>
        extends ContainerSerializer<T>
        implements ContextualSerializer
    {
        protected final JavaType _elementType;
    
        /**
         * Collection-valued property being serialized with this instance
         */
        protected final BeanProperty _property;
    
        protected final boolean _staticTyping;
    
        /**
         * Setting for specific local override for "unwrap single element arrays":
         * true for enable unwrapping, false for preventing it, `null` for using
         * global configuration.
         *
         * @since 2.6
         */
        protected final Boolean _unwrapSingle;
    
        /**
         * Type serializer used for values, if any.
         */
        protected final TypeSerializer _valueTypeSerializer;
    
        /**
         * Value serializer to use, if it can be statically determined
         */
        protected final JsonSerializer<Object> _elementSerializer;
    
        /**
         * If element type cannot be statically determined, mapping from
         * runtime type to serializer is handled using this object
         */
        protected PropertySerializerMap _dynamicSerializers;
    
        /*
        /**********************************************************
        /* Life-cycle
        /**********************************************************
         */
    
        /**
         * Non-contextual, "blueprint" constructor typically called when the first
         * instance is created, without knowledge of property it was used via.
         *
         * @since 2.6
         */
        protected AsArraySerializerBase(Class<?> cls, JavaType et, boolean staticTyping,
                TypeSerializer vts, JsonSerializer<Object> elementSerializer)
        {
            this(cls, et, staticTyping, vts, null, elementSerializer, null);
        }
    
        /**
         * @deprecated Since 2.6 Use variants that either take 'src', or do NOT pass
         *    BeanProperty
         */
        @Deprecated
        protected AsArraySerializerBase(Class<?> cls, JavaType et, boolean staticTyping,
                TypeSerializer vts, BeanProperty property, JsonSerializer<Object> elementSerializer)
        {
            this(cls, et, staticTyping, vts, property, elementSerializer, null);
        }
    
        /**
         * General purpose constructor. Use contextual constructors, if possible.
         *
         * @since 2.12
         */
        @SuppressWarnings("unchecked")
        protected AsArraySerializerBase(Class<?> cls, JavaType elementType, boolean staticTyping,
                TypeSerializer vts, BeanProperty property, JsonSerializer<?> elementSerializer,
                Boolean unwrapSingle)
        {
            // typing with generics is messy... have to resort to this:
            super(cls, false);
            _elementType = elementType;
            // static if explicitly requested, or if element type is final
            _staticTyping = staticTyping || (elementType != null && elementType.isFinal());
            _valueTypeSerializer = vts;
            _property = property;
            _elementSerializer = (JsonSerializer<Object>) elementSerializer;
            _dynamicSerializers = PropertySerializerMap.emptyForProperties();
            _unwrapSingle = unwrapSingle;
        }
    
        @SuppressWarnings("unchecked")
        protected AsArraySerializerBase(AsArraySerializerBase<?> src,
                BeanProperty property, TypeSerializer vts, JsonSerializer<?> elementSerializer,
                Boolean unwrapSingle)
        {
            super(src);
            _elementType = src._elementType;
            _staticTyping = src._staticTyping;
            _valueTypeSerializer = vts;
            _property = property;
            _elementSerializer = (JsonSerializer<Object>) elementSerializer;
            // [databind#2181]: may not be safe to reuse, start from empty
            _dynamicSerializers = PropertySerializerMap.emptyForProperties();
            _unwrapSingle = unwrapSingle;
        }
    
        /**
         * @deprecated since 2.6: use the overloaded method that takes 'unwrapSingle'
         */
        @Deprecated
        protected AsArraySerializerBase(AsArraySerializerBase<?> src,
                BeanProperty property, TypeSerializer vts, JsonSerializer<?> elementSerializer)
        {
            this(src, property, vts, elementSerializer, src._unwrapSingle);
        }
        
        /**
         * @deprecated since 2.6: use the overloaded method that takes 'unwrapSingle'
         */
        @Deprecated
        public final AsArraySerializerBase<T> withResolved(BeanProperty property,
                TypeSerializer vts, JsonSerializer<?> elementSerializer) {
            return withResolved(property, vts, elementSerializer, _unwrapSingle);
        }
    
        /**
         * @since 2.6
         */
        public abstract AsArraySerializerBase<T> withResolved(BeanProperty property,
                TypeSerializer vts, JsonSerializer<?> elementSerializer,
                Boolean unwrapSingle);
    
        /*
        /**********************************************************
        /* Post-processing
        /**********************************************************
         */
        
        /**
         * This method is needed to resolve contextual annotations like
         * per-property overrides, as well as do recursive call
         * to <code>createContextual</code> of content serializer, if
         * known statically.
         */
        @Override
        public JsonSerializer<?> createContextual(SerializerProvider serializers,
                BeanProperty property)
            throws JsonMappingException
        {
            TypeSerializer typeSer = _valueTypeSerializer;
            if (typeSer != null) {
                typeSer = typeSer.forProperty(property);
            }
            JsonSerializer<?> ser = null;
            Boolean unwrapSingle = null;
            // First: if we have a property, may have property-annotation overrides
            
            if (property != null) {
                final AnnotationIntrospector intr = serializers.getAnnotationIntrospector();
                AnnotatedMember m = property.getMember();
                if (m != null) {
                    Object serDef = intr.findContentSerializer(m);
                    if (serDef != null) {
                        ser = serializers.serializerInstance(m, serDef);
                    }
                }
            }
            JsonFormat.Value format = findFormatOverrides(serializers, property, handledType());
            if (format != null) {
                unwrapSingle = format.getFeature(JsonFormat.Feature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED);
            }
            if (ser == null) {
                ser = _elementSerializer;
            }
            // 18-Feb-2013, tatu: May have a content converter:
            ser = findContextualConvertingSerializer(serializers, property, ser);
            if (ser == null) {
                // 30-Sep-2012, tatu: One more thing -- if explicit content type is annotated,
                //   we can consider it a static case as well.
                if (_elementType != null) {
                    if (_staticTyping && !_elementType.isJavaLangObject()) {
                        ser = serializers.findContentValueSerializer(_elementType, property);
                    }
                }
            }
            if ((ser != _elementSerializer)
                    || (property != _property)
                    || (_valueTypeSerializer != typeSer)
                    || (!Objects.equals(_unwrapSingle, unwrapSingle))) {
                return withResolved(property, typeSer, ser, unwrapSingle);
            }
            return this;
        }
    
        /*
        /**********************************************************
        /* Accessors
        /**********************************************************
         */
        
        @Override
        public JavaType getContentType() {
            return _elementType;
        }
    
        @Override
        public JsonSerializer<?> getContentSerializer() {
            return _elementSerializer;
        }
    
        /*
        /**********************************************************
        /* Serialization
        /**********************************************************
         */
    
        // NOTE: as of 2.5, sub-classes SHOULD override (in 2.4 and before, was final),
        // at least if they can provide access to actual size of value and use `writeStartArray()`
        // variant that passes size of array to output, which is helpful with some data formats
        @Override
        public void serialize(T value, JsonGenerator gen, SerializerProvider provider) throws IOException
        {
            if (provider.isEnabled(SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED)
                    && hasSingleElement(value)) {
                serializeContents(value, gen, provider);
                return;
            }
            gen.writeStartArray(value);
            serializeContents(value, gen, provider);
            gen.writeEndArray();
        }
    
        @Override
        public void serializeWithType(T value, JsonGenerator g, SerializerProvider provider,
                TypeSerializer typeSer) throws IOException
        {
            WritableTypeId typeIdDef = typeSer.writeTypePrefix(g,
                    typeSer.typeId(value, JsonToken.START_ARRAY));
            // [databind#631]: Assign current value, to be accessible by custom serializers
            g.setCurrentValue(value);
            serializeContents(value, g, provider);
            typeSer.writeTypeSuffix(g, typeIdDef);
        }
    
        protected abstract void serializeContents(T value, JsonGenerator gen, SerializerProvider provider)
            throws IOException;
    
        @SuppressWarnings("deprecation")
        @Override
        public JsonNode getSchema(SerializerProvider provider, Type typeHint)
            throws JsonMappingException
        {
            ObjectNode o = createSchemaNode("array", true);
            if (_elementSerializer != null) {
                JsonNode schemaNode = null;
                if (_elementSerializer instanceof SchemaAware) {
                    schemaNode = ((SchemaAware) _elementSerializer).getSchema(provider, null);
                }
                if (schemaNode == null) {
                    schemaNode = com.fasterxml.jackson.databind.jsonschema.JsonSchema.getDefaultSchemaNode();
                }
                o.set("items", schemaNode);
            }
            return o;
        }
    
        @Override
        public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint)
            throws JsonMappingException
        {
            JsonSerializer<?> valueSer = _elementSerializer;
            if (valueSer == null) {
                // 19-Oct-2016, tatu: Apparently we get null for untyped/raw `EnumSet`s... not 100%
                //   sure what'd be the clean way but let's try this for now:
                if (_elementType != null) {
                    valueSer = visitor.getProvider().findContentValueSerializer(_elementType, _property);
                }
            }
            visitArrayFormat(visitor, typeHint, valueSer, _elementType);
        }
    
        protected final JsonSerializer<Object> _findAndAddDynamic(PropertySerializerMap map,
                Class<?> type, SerializerProvider provider) throws JsonMappingException
        {
            PropertySerializerMap.SerializerAndMapResult result = map.findAndAddSecondarySerializer(type, provider, _property);
            // did we get a new map of serializers? If so, start using it
            if (map != result.map) {
                _dynamicSerializers = result.map;
            }
            return result.serializer;
        }
    
        protected final JsonSerializer<Object> _findAndAddDynamic(PropertySerializerMap map,
                JavaType type, SerializerProvider provider) throws JsonMappingException
        {
            PropertySerializerMap.SerializerAndMapResult result = map.findAndAddSecondarySerializer(type, provider, _property);
            if (map != result.map) {
                _dynamicSerializers = result.map;
            }
            return result.serializer;
        }
    }
    

    com/fasterxml/jackson/databind/ser/std/AsArraySerializerBase.java

     

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